Editing Calculator (section)

===Pocket calculators===
{{Redirect|Pocket calculator|the song|Computer World}}
[[File:2010 CURTA-Calculator 08.jpg|alt=A person's hand is holding a small, metallic cylinder with a crank sticking out. |thumb|[[curta|The first pocket calculator]] used a crank instead of electronics.<ref name="FirstPocketCalculator" />]]
Released in 1947, the first pocket calculator which could perform the four basic arithmetic functions with digital precision was the [[Curta]], a mechanical device operated by a crank, bearing “an uncanny resemblance to a pepper grinder”.<ref name="FirstPocketCalculator" /> The readout was digital with eleven digits of precision. For comparison, the contemporaneous [[Slide rule|ten inch slide rule]] used analog calculation to approximate answers to only four digits of precision.<ref>{{Cite book |last1=Harris |first1=Charles Overton |url=https://catalog.hathitrust.org/Record/005735914 |title=Slide rule simplified |last2=American Technical Society. |publisher=American technical society |year=1944 |location=Chicago}}</ref> The Curta remained the finest pocket calculator available for a quarter of a century.<ref name="FirstPocketCalculator">{{Cite journal |last=Stoll |first=Cliff |date=2004 |title=the Curious History of the First Pocket Calculator |url=https://www.jstor.org/stable/26172659 |journal=Scientific American |volume=290 |issue=1 |pages=92–99 |doi=10.1038/scientificamerican0104-92 |jstor=26172659 |pmid=14682043 |bibcode=2004SciAm.290a..92S |issn=0036-8733|url-access=subscription }}</ref>

By 1970, a calculator could be made using just a few chips of low power consumption, allowing portable models powered from rechargeable batteries. {{anchor|Cal Tech}}The first handheld calculator was a 1967 prototype called '''''Cal Tech''''', whose development was led by [[Jack Kilby]] at [[Texas Instruments]] in a research project to produce a portable calculator. It could add, multiply, subtract, and divide, and its output device was a paper tape.<ref>{{cite web |website=Education Technology |date=15 August 2002 |url=http://education.ti.com/educationportal/sites/US/nonProductSingle/about_press_release_news37.html |title=Texas Instruments Celebrates the 35th Anniversary of Its Invention of the Calculator |url-status=dead |archive-url=https://web.archive.org/web/20080627144010/http://education.ti.com/educationportal/sites/US/nonProductSingle/about_press_release_news37.html |archive-date=2008-06-27 |publisher=[[Texas Instruments]]}}</ref><ref>{{cite web |url=https://www.npr.org/templates/story/story.php?storyId=14845433 |title=Electronic Calculator Invented 40 Years Ago |url-status=live |archive-url=https://web.archive.org/web/20081205151504/http://www.npr.org/templates/story/story.php?storyId=14845433 |archive-date=2008-12-05 |work=All Things Considered |publisher=NPR |date=30 September 2007}} Audio interview with one of the inventors.</ref><ref>{{cite news |title=50 Jahre Taschenrechner – Die Erfindung, die niemand haben wollte |language=de |trans-title=50th anniversary of calculators – the invention not wanted by anyone |work=[[Frankfurter Allgemeine Zeitung]] (FAZ) |date=2017-03-27 |url=https://www.faz.net/aktuell/wirtschaft/wirtschaftswissen/50-jahre-taschenrechner-die-erfindung-die-niemand-haben-wollte-14944569.html |access-date=2017-03-30 |archive-url=https://web.archive.org/web/20170329202602/https://www.faz.net/aktuell/wirtschaft/wirtschaftswissen/50-jahre-taschenrechner-die-erfindung-die-niemand-haben-wollte-14944569.html |archive-date=2017-03-29 |url-status=live}}</ref><ref>{{cite magazine |last=May |first=Mike |title=How the Computer Got Into Your Pocket |magazine=[[American Heritage of Invention & Technology]] |date=Spring 2000 |volume=15 |issue=4 |pages=42–54 |url=https://www.dropbox.com/s/bwwc9q3y090d2r8/How_the_Computer_Got_Into_Your_Pocket.pdf |access-date=2017-03-30}}</ref><ref>{{cite magazine |title=The Texas Edison |author-first=T. R. |author-last=Reid |magazine=[[Texas Monthly]] |date=July 1982}}</ref><ref>{{cite magazine |title=The First Handheld Digital Calculator Celebrates 50 Years |url=http://electronicdesign.com/analog/first-handheld-digital-calculator-celebrates-50-years-part-1 |archive-url=https://web.archive.org/web/20170413153616/http://electronicdesign.com/analog/first-handheld-digital-calculator-celebrates-50-years-part-1 |archive-date=2017-04-13 |url-status=live |date=2017-03-27 |magazine=Electronic Design |first=Thomas |last=Okon}}</ref> As a result of the "Cal-Tech" project, Texas Instruments was granted master patents on portable calculators.{{efn|The Japanese Patent Office granted a patent in June 1978 to Texas Instruments (TI) based on US patent 3819921, notwithstanding objections from 12 Japanese calculator manufacturers. This gave TI the right to claim royalties retroactively to the original publication of the Japanese patent application in August 1974. A TI spokesman said that it would actively seek what was due, either in cash or technology cross-licensing agreements. 19 other countries, including the United Kingdom, had already granted a similar patent to Texas Instruments.<ref>{{Cite journal |date=August 17, 1978 |title=New from Texas Instruments: The World's Most Powerful Pocket Calculator |url=https://books.google.com/books?id=-U8eAQAAMAAJ&q=Texas%20Instruments |journal=[[New Scientist]] |pages=455 |via=[[Google Books]]}}</ref><ref>{{Cite journal |date=October 1978 |title=Patent Victory |url=https://www.worldradiohistory.com/UK/Practical-Electronics/70s/Practical-Electronics-1978-10.pdf |journal=[[Practical Electronics]] |volume=14 |issue=14 |pages=1095 |via=World Radio History}}</ref>}}

The first commercially produced portable calculators appeared in Japan in 1970, and were soon marketed around the world. These included the [[Sanyo]] ICC-0081 "Mini Calculator", the [[Canon (company)|Canon]] Pocketronic, and the [[Sharp QT-8B]] "micro Compet". The Canon Pocketronic was a development from the "Cal-Tech" project. It had no traditional display; numerical output was on thermal paper tape.

Sharp put in great efforts in size and power reduction and introduced in January 1971 the [[Sharp EL-8]], also marketed as the Facit 1111, which was close to being a pocket calculator. It weighed 1.59 pounds (721 grams), had a [[vacuum fluorescent display]], rechargeable [[NiCad]] batteries, and initially sold for US$395.

However, [[integrated circuit development]] efforts culminated in early 1971 with the introduction of the first "calculator on a chip", the MK6010 by [[Mostek]],<ref>"Single Chip Calculator Hits the Finish Line", ''Electronics'', February 1, 1971, p. 19.</ref> followed by Texas Instruments later in the year. Although these early hand-held calculators were very costly, these advances in electronics, together with developments in display technology (such as the [[vacuum fluorescent display]], [[LED]], and [[LCD]]), led within a few years to the cheap pocket calculator available to all.

In 1971, [[Pico Electronics]]<ref>{{cite web |url=http://www.spingal.plus.com/micro |author=James McGonigal |date=September 2010 |orig-year=September 2006 |title=Microprocessor History – Foundations in Glenrothes, Scotland |publisher=Spingal.plus.com |access-date=2011-07-19 |url-status=dead |archive-url=https://web.archive.org/web/20110720142104/http://www.spingal.plus.com/micro/ |archive-date=2011-07-20}}</ref> and [[General Instrument]] also introduced their first collaboration in ICs, a full single chip calculator IC for the Monroe Royal Digital III calculator. Pico was a spinout by five GI design engineers whose vision was to create single chip calculator ICs. Pico and GI went on to have significant success in the burgeoning handheld calculator market.

The first truly pocket-sized electronic calculator was the [[Busicom]] LE-120A "HANDY", which was marketed early in 1971.<ref>{{cite magazine |title=The one-chip calculator is here, and it's only the beginning |magazine=Electronic Design |date=February 18, 1971 |page=34}}</ref> Made in Japan, this was also the first calculator to use an LED display, the first hand-held calculator to use a single integrated circuit (then proclaimed as a "calculator on a chip"), the [[Mostek]] MK6010, and the first electronic calculator to run off replaceable batteries. Using four AA-size cells the LE-120A measures {{convert|4.9 x 2.8 x 0.9|in|mm}}.

The first European-made pocket-sized calculator, DB 800<ref>{{cite web |url=http://www.epocalc.net/pages/calc_premieres |title=The first portable calculators |website=epocalc |access-date=30 December 2016 |url-status=dead |archive-url=https://web.archive.org/web/20161028020141/http://www.epocalc.net/pages/calc_premieres |archive-date=28 October 2016}}</ref><ref>{{cite web|url=http://www.jutarnji.hr/40--rodendan-digitrona--u-bujama-je-izraden-prvi-europski-dzepni-kalkulator--te-1971-kostao-je-koliko-i-fico/954368/ |title=U Bujama je izrađen prvi europski džepni kalkulator. Te 1971. koštao je koliko i fićo |trans-title=The first European pocket calculator was made in Buje. In 1971, it cost as much as a son|language=hr|date=20 June 2011 |access-date=30 December 2016|url-status=dead|archive-url=https://web.archive.org/web/20160304003213/http://www.jutarnji.hr/40--rodendan-digitrona--u-bujama-je-izraden-prvi-europski-dzepni-kalkulator--te-1971-kostao-je-koliko-i-fico/954368/|archive-date=4 March 2016}}</ref> was made in May 1971 by [[Digitron (company)|Digitron]] in [[Buje]], [[Croatia]] (former [[Socialist Federal Republic of Yugoslavia|Yugoslavia]]) with four functions and an eight-digit display and special characters for a negative number and a warning that the calculation has too many digits to display.

The first American-made pocket-sized calculator, the Bowmar 901B (popularly termed ''The Bowmar Brain''), measuring {{convert|5.2 x 3.0 x 1.5|in|mm}}, came out in the Autumn of 1971, with four functions and an eight-digit red LED display, for {{US$|240}}, while in August 1972 the four-function [[Sinclair Executive]] became the first slimline pocket calculator measuring {{convert|5.4 x 2.2 x 0.35|in|mm}} and weighing {{convert|2.5|oz|g}}. It retailed for around £79 ({{US$|194}} at the time). By the end of the decade, similar calculators were priced less than £5 (${{To USD|5|GBR}}). Following protracted development over the course of two years including a botched partnership with Texas Instruments, [[Eldorado Electrodata]] released five pocket calculators in 1972. One called the Touch Magic was "no bigger than a pack of cigarettes" according to ''Administrative Management''.<ref>{{cite journal |last=Bellotto |first=Sam Jr. |date=August 1972 |title=Calculators: They Just Keep Multiplying |pages=68–73 |url=https://archive.org/details/sim_administrative-management_1972-08_33_8/page/n67 |journal=Administrative Management |volume=33 |issue=8 |publisher=Geyer-McAllister Publications |via=Internet Archive}}</ref>

The first [[Soviet Union]] made pocket-sized calculator, the ''Elektronika B3-04''<ref>{{Cite web |url=http://www.leningrad.su/museum/show_calc.php?n=26 |publisher=Soviet Digital Electronics Museum |title=ELEKTRONIKA B3-04 |work=Коллекция советской цифровой электроники |trans-work=Collection of Soviet digital electronics}}</ref> was developed by the end of 1973 and sold at the start of 1974.

One of the first low-cost calculators was the [[Sinclair Cambridge]], launched in August 1973. It retailed for £29.95 (${{To USD|29.95|GBR}}), or £5 (${{To USD|5|GBR}}) less in kit form, and later models included some scientific functions. The Sinclair calculators were successful because they were far cheaper than the competition; however, their design led to slow and less accurate computations of [[transcendental function]]s (maximum three decimal places of accuracy).<ref>{{cite web |url=http://righto.com/sinclair |title=Reversing Sinclair's amazing 1974 calculator hack – half the ROM of the HP-35 |website=Ken Shirriff's blog}} See in particular the section "Limited performance and accuracy". For more coverage of Shirriff's results, see {{cite news |first=Simon |last=Sharwood |date=September 2, 2013 |title=Google chap reverse engineers Sinclair Scientific Calculator |newspaper=The Register |url=https://www.theregister.co.uk/2013/09/02/google_chap_reverse_engineers_sinclair_scientific_calculator/ |archive-url=https://web.archive.org/web/20170823073444/https://www.theregister.co.uk/2013/09/02/google_chap_reverse_engineers_sinclair_scientific_calculator/ |archive-date=August 23, 2017 |url-status=live}}</ref>